Do not be intimidated by its size. Though massive, it is very easy to kill. The following was done under the Medium difficulty setting. Upon starting the fight, notice you are "caged in" by the Boss' tentacles. Notice the yellow "blooms" around the Boss' mouth. Shooting each one will get you closer to killing it. However, upon shooting a few of them, the boss Grabs you, holding you in the air. During this time, it appears that you are helpless. Aim whatever weapon you are using at the time and shoot the yellow blooms. After a few shots you will be dropped. The Boss will then begin slamming its tentacles at you more frequently. They are very easy to avoid. Strafe left to right constantly. They will never hit you. The Boss will roar, shoot a few exploding cells at you, or will drop enemy pods upon you. This is part is also easy, considering it is usually only two small Necromorphs. After you destroy the blooms, you will notice a "caged" area underneath the beast. Under this rib cage lies its many hearts. Again, use same strategy with the whole tentacle scenario. After a few times, the Boss will have his fit and open up again. Unload and the Boss will come tumbling down.